A DNA sequencer is an apparatus that determine the order (or sequence) of the nucleotide bases (adenine, guanine, cytosine, and thymine) in a sample of DNA. With one sequencing technique, DNA is extracted from a bio-sample and purified. The purified DNA is lysed, and fragments thereof are replicated through polymerase chain reaction (PCR). A reference material containing synthesized fragments of known fragment sizes is added to the sample containing the replicated fragments. The DNA and reference fragments are labeled with target specific fluorescent dyes, each with a known and unique spectral response, and the labeled fragments are separated through electrophoresis. An optical component transmits radiation, having a wavelength within a predetermined wavelength range, which irradiates and excites the dyes of the separated fragments, receives characteristic fluorescent radiation emitted by the dyes in response to being irradiated, and generates electrical signals indicative of the received characteristic fluorescent radiations. The signal corresponding to the DNA under evaluation is used to sequence the DNA fragments by nucleotide base based on the spectral characteristics.
The signal corresponding to the reference material may be used to verify calibration and/or functionality of the sequencer. Unfortunately, the DNA and reference material are concurrently processed. As a consequence, if the signal corresponding to the reference material indicates that the sequencer is out of calibration or not functioning properly, the sequencer results are discarded, the sample is disposed, and another sample has to be obtained, prepared, and processed after the sequencer is re-calibrated and its functionality is verified. However, even after re-calibration and verification, external forces, temperature, vibrations, shock, and/or other influences, for example, from the time of calibration to the time of use, may throw the calibrated and verified system out of calibration, and this may not be detected until after the concurrent processing of another DNA sample and reference material. As discussed above, this may lead to discarding the results, disposing of the sample, re-calibration of the sequencer, and processing of another sample, if the signal corresponding to the reference material indicates that the sequencer is out of calibration or not functioning properly.